DENVER - Denver's 18-year-old ban on pit bulls is under a new court challenge, this time by three dog owners who say it is unfair to single out one breed.

The suit also claims that pit bull owners are forced to admit guilt to save their dogs, the Denver Post reported. Under the law, confiscated pit bulls will be returned if the owners agree to move them from the city. The dogs also get an identification microchip.

The city adopted the ban in 1989 after a pit bull killed a young child and badly injured a grown man.

But opponents of the ban say the problem is not pit bulls, it is owners who fail to train them properly.

"Your No. 1 dog biters of children actually are cocker spaniels," American Canine Association president Bob Yarnall told the Post. "You can't be prejudiced against a breed of dog."